title: Physiology of the pulmonary circulation and the right heart.
abstract: The pulmonary circulation is a high-flow and low-pressure circuit. The functional state of the pulmonary circulation is defined by pulmonary vascular pressure-flow relationships conforming to distensible vessel models with a correction for hematocrit. The product of pulmonary arterial compliance and resistance is constant, but with a slight decrease as a result of increased pulsatile hydraulic load in the presence of increased venous pressure or proximal pulmonary arterial obstruction. An increase in left atrial pressure is transmitted upstream with a ratio ≥1 for mean pulmonary artery pressure and ≤1 the diastolic pulmonary pressure. Therefore, the diastolic pressure gradient is more appropriate than the transpulmonary pressure gradient to identify pulmonary vascular disease in left heart conditions. Exercise is associated with a decrease in pulmonary vascular resistance and an increase in pulmonary arterial compliance. Right ventricular function is coupled to the pulmonary circulation with an optimal ratio of end-systolic to arterial elastances of 1.5-2.
authors.affiliation: Department of Physiology, Erasme Campus of the Free University of Brussels, CP 604, 808, Lennik Road, 1070, Brussels, Belgium, rnaeije@ulb.ac.be.
authors.forename: Robert
authors.initials: R
authors.lastname: Naeije
mesh_terms: D000818:Animals; D015444:Exercise; D006321:Heart / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008168:Lung / Q000098:blood supply*; D011652:Pulmonary Circulation / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology